Suction packaging apparatus



Jan. 16, 1968 R. G. KING 3,363,395v

SUCTIONPACKAGING APPARATUS Original Filed Dec. 21, 1961 2 Sheets-Sheet 1INVENTOR fizcgaz'a G. ".7815

Jan. 16, 1968 R. G. KING 7 3,

SUCTION PACKAGING APPARATUS Griginal Filed Dec. 21, 1961 2 Sheets-Sheet2 INVENTOR.

Pit/5 1a GT Z2237- United States Patent 3,363,395 SUCTION PACKAGINGAPPARATUS Richard G. King, Chicago, 111., assignor to Cloud MacMneCorporation, Skokie, Iii, a corporation of Delaware Original applicationDec. 21, 1961, Ser. No. 161,961, new Patent No. 3,216,832, dated Nov. 9,1965. Divided and this application Feb. 19, 1965, Ser. No. 434,069

1 Claim. (Cl. 53-412) The present application is a division ofapplication Ser. No. 161,061 filed Dec. 21, 1961, now Patent No.3,216,832.

In the field of stretch wrapping, or packaging products in film, it issometimes desirable to suck air out of the package after it is initiallyformed, and then seal the package so that the product is protected fromcontact with air. Machines for performing such suction packaging havebeen satisfactorily built and operated before the present invention.

According to the present invention, a method of packaging is developedby which such machines are made more efficient and more satisfactory forsome products of irregular shape, typified by a plurality of sausages.This is accomplished by premolding the package-forming films to theirregular shape of such products. By premolding the film tosubstantially its desired shape before evacuation thereof is commencedthere is less interstitial space from which the air must be drawn, andmore certainty of adequate evacuation. In the illustrated apparatus forperforming my method, and which also embodies my invention, thepremolding of the film is accomplished by providing ribs along thepreviously smooth mold surfaces, these ribs conforming to the shape ofthe product to be pack-aged.

This contour premolding increases efiiciency in reducing the amount ofpower required for pumping. It also makes possible the allowance of lesstime for the evacuating of the package and therefore a speeding up ofthe packaging process.

It also results in better keeping qualities. It should be understoodthat with respect to many products, as for example, many foods, one ofthe reasons for the removal of air from the package is to improve thekeeping qualities of the product. Often the oxygen in the atmosphere hasa deleterious effect upon the product. In the past it has been assumedthat an effective job of oxygen removal has been accomplished in vacuumpackaging when the films of the finished package appeared to have beensatisfactorily drawn into cont-act with the surfaces of the product.According to the present invention, however, it has been recognized thatthis is not always true with irregularly shaped articles; and thepreshaping method of this invention gives adequate evacuation morereliably. It also facilitates separating the items within one package,when desired.

The present invention also results more reliably in the desired packageattractiveness. It avoids wrinkles, which have previously occurred andavoids some instances of flattening of the product.

Additional objects and advantages of the invention will be apparent fromthe following description and from the drawings.

Designation of figures FIGURE 1 is a perspective view of one form of thepackage which can be more eificiently produced according to the presentinvention.

FIGURE 2 is a vertical sectional view through a mold embodying thepresent invention for producing the package of FIG. 1.

FIGURE 3 is a fragmentary view similar to FIG. 2 showing the moldclosed.

3,363,395 Patented Jan. 16, 1968 ICC FIGURE 4 is a fragmentary view ofthe same mold with the bottom plate deeper in the mold to provide fortwo layers of the sausages or the like comprising the wrapped product.

FIGURE 5 is a vertical sectional view taken approximately about the line5-5 of FIG. 3.

FIGURE 5A is a fragmentary view showing the contouring of the ends ofthe mold recesses in FIG. 5.

FIGURE 6 is a plan view of a mold contoured for a different article,with the article being packaged therein.

FIGURE 7 is a vertical sectional view taken approximately along the line77 of FIG. 6, showing especially the cross section of the contouredbottom plate of the mold.

Intent clause Although the following disclosure offered for publicdissemination is detailed to ensure adequacy and aid understanding, thisis not intended to prejudice that purpose of a patent which is to covereach new inventive concept therein no matter how others may laterdisguise it by variations in form or additions or further improvements.The claims at the end hereof are intended as the chief aid toward thispurpose, as it is these that meet the requirements of pointing out theparts, improvements or combinations in which the inventive concepts arefound.

General description-background The method of this invention is bestexplained :by reference to its performance in specific apparatus. Inmany respects the apparatus may correspond to that shown in the CharlesE. Cloud Patent 2,888,787. FIGURE 1 represents a type of package whichmight be formed on the machine of that patent, but which is betterformed by the present method. In the illustration, the product comprisesfive frankfurters 11. They-are packaged between two films 12 and 13 ofstretch-wrap material which are sealed together peripherally. Air hasbeen evacuated from the package to draw the film into snug engagementwith the product.

Although FIGURE 2 includes features of the present invention, it alsoincludes the basic features taught by the Cloud patent. Thus, a lower orbase mold 114- forms a pocket into which the lower film 13 is drawn sothat a pocket is also formed in it. After the product is placed in thispocket, the upper film 12 is sealed across it. A perforation 16 isformed in the upper film 12 in alignment with a venting notch 17 formedin the lower film by virtue of its following the contour of a similarnotch in the mold 14. A cover plate 18 is now laid across the mold 114sealing it off, and air from within the package, that is, from betweenthe films 12 and 13, is drawn out through suction hose 19, passage 21,perforation 16 and notch'17. During this evacuation, the same highvacuum may be applied to base mold 114 through tube 22, which would havebeen used earlier with a lower vacuum for sucking the film 13 into themold. After the air has been evacuated from the package, air is admittedthrough tube 22 to collapse the package and seal lower film 13 overperforation 16, thereby sealing the package against the readmission ofair.

As illustrated in the patent, the bottom of the mold was fiat and hencethe lower film 13 was drawn to the shape of a flat-bottomed pocket.Likewise the cap plate 18 was flat on its inner side.

The Cloud type of machine worked very well on the types of productillustrated in that patent. On other types of product, the Cloud machinedid not seem to work as perfectly.

Contour premoldz'ng According to the present invention the causes ofimperfections in operation of the Cloud machine with some types ofpackages has been recognized, and a remedy for the trouble has beenprovided. The trouble arose from the fact that there were depressions inthe outer surfaces of some types of products. In the finished productthe film obviously had been drawn into these depressions by vacuum, andthe cause of imperfections wasnt readily determined. Even afterobserving that sometimes the evacuation did not seem to be as good asdesired, there was still a problem of how to make it better. Accordingto the present invention, these causes have been determined to be mainlyof three related natures.

(1) The depressions increased the amount of vacant space within thepackage from which air had to be withdrawn, and accordingly it increasedthe amount of air to be withdrawn. Time which was sufiicient forwithdrawing the air from other packages was not sufiicient forwithdrawing the air from these packages.

(2) Partly because of inadequate evacuation time, and partly for otherreasons, the films did not contact the surfaces of the product asuniformly as in the case of more easily packaged articles, and theresulting exposure of air within the package caused more deteriorationof the packaged product than was expected of the packages from the Cloudmachine.

(3) If the application of external air pressure closed the evacuationpackage before completing the collapse of the package it would trapslightly more residual air within the package than would otherwise bethe case.

According to the present invention, these causes of trouble are reducedor substantially eliminated by preshaping the film to conform to thedepressions of the product, so that there is less space to be evacuated,so that the film more readily is drawn into contact with the producteven in the area of the depressions, and so that less residual oxygen isenclosed.

As seen in FIGURE 2, the preshaping of the bottom film is performed byusing a bottom mold plate 24 provided with upstanding ribs or ridges 26to fit the depressions within the product, namely the spaces between thesausages. It is apparent from FIGURE 2 that the lower ribs 26 havepreformed the film 13, as it was drawn into the pocket, to approximatelyfit the lower surface of the product. Likewise, the top mold plate orcap 18 is provided with ribs 27 extending downwardly so that they alsofit the depressions in the product or the spaces between the members ofthe product. As seen in FIGURE 3, the lowering of the cap 18 over themold will preform the upper film 12 in the like manner.

It might seem, from FIGURE 2, that the sausages are spaced so far apartthat there would be extra space between them to be evacuated instead ofless. However, as seen in FIGURE 3, the fingers 25 and 27 press therespective films 12 and 13 almost into contact with one another. Hence,there is only a very minimum space, in the end, to be evacuated.

FIGURES and 5A show other views of the structure in FIGURES 2 and 3,showing especially the partly spherical contouring of bottom plate 24 tocorrespond to the shape of the ends of the frankfurters. This isimportant, especially if the film is used which does not contractelastically, to avoid wrinkles due to excess areas of material.

According to another feature of the invention, the same contoured bottomplate 24 may be used for a single layer of sausages as in FIGURE 2, orfor two layers of sausages as in FIGURE 4. In FIGURE 4, the contouredbottom plate 24 rests on the bottom of cavity 29 of base mold 14. Thisprovides a mold combination comprising contour bottom plate 24 and theside walls 31 of base mold 14, suitable for two layers of sausages 11.When only one layer of sausages is to be packaged, the bottom contourplate 24 is rested on a rack 33 of any suitable form which holds thecontour bottom plate 24 at the right elevation for a single layer ofsausages.

The rack 33 has been shown as formed of two bars 34 of the desiredvertical dimension and held in proper relationship with one another by adowel 36 which may have a press fit with the bars 34. Flow of air passthe bars 34 may be ensured by grooves 37. Since the bars fit loosely,these grooves probably are not needed, and frankly their purpose may bemore to show in the drawing that there is communication past the bars34- than because of real necessity for their use.

FIGURES 6 and 7 illustrate another shape with respect to which thecontour mold concept of this invention is useful, even though it is notas easy to obtain good interfitting between the product and the contourof the mold as in the case of FIGURES 1 to 5. In FIGURE 6 the product isa spread-out stack of slices of food product such as cheese or meat. Thespreading out is desirable for ease in separation of the slices as wellas for attractiveness in the store. Nevertheless, such spreading out orlapping presents the problem of interstitial spaces from which air mustbe withdrawn. As illustrated in FIGURE 7, upstanding ribs 41 areprovided to interfit with the contour of the sliced product to bepackaged. Preferably in this case the ribs 4 1 are arcuate in shape, ifthe slices are round as seen in FIGURE 3. The cap for the mold shown inFIGURE 7 may be similarly provided with ribs, although these ribs wouldlie mainly to the right when the ribs 41 are mainly to the left.

It will be observed that in addition to having ribs 41, the contourbottom plate 42 of FIGURE 7 is concave on its upper face andnonsymmetrical so as to fit the nonsymmetrical product.

Packagers often desire to have the individual products such asfrankfurters sealed in isolation from one another. It might seem fromFIGURE 3 that this would not result, but in fact the two films, whenpressed close to one another by ribs 26 and 27, will usually be pressedtogether by external air pressure when applied at the end of theevacuation. As a matter of fact, it has been found that this result canbe achieved, even with a simplified version of the method in which theribs 27 are omitted, and only the lower film is precontoured. In thisevent, however, it may be necessary to use ribs a little higher than theribs 26 as shown so as to press the film to or even a little beyond thepoints at which the frankfurters are closest together. The height towhich the lower film 16 will need to be pre-contoured will dependsomewhat on the stretching characteristics of the films, and especiallyof upper film 12.

Although this version of the method in which the upper film is notpie-contoured does not achieve the maximum advantages of the inventionfrom the standpoint of minimizing the space to be evacuated andminimizing the residual air, it has been found to do a satisfactory job.

Even without pre-contouring the upper film, the precontouring of thelower film has proved to be extremely important. It makes a greatdifference in the finished package in some instances. For example, it isvery difiicult without it to achieve isolation of the frankfurters fromone another. It is also diificult without at least this lowerpro-contouring to avoid a flattening of the adjacent sides of thefrankfurters as the collapsing process tends to squeeze them together.

Pie-contouring the bottom film makes it possible to keep thefrankfurters separated and reliably avoid wrinkles in the film on thatside of the sausages so that this side has an extremely attractiveappearance and may well be the side chosen for display, even though theother side may not be noticeably inferior.

For proper pro-contouring it is necessary to be sure that the film isdrawn fully into the mold. This may or may not result from the fact thatthe bottom plates 24 or 42 fit loosely in the main mold body as 14 sothat air can be drawn around the edges of the bottom plates. If it isfound that the film as it stretches seals off any of the pockets orrecesses into which it is intended to be drawn, air passages 46 shouldbe provided at critical points. These also aid in quick collapsing ofthe film after evacuation.

The present invention is to be distinguished from packaging of the pastin which the simplest possible shaping of the pocket happened to be thesame as that of the product. Here there is special contour shaping ofnon symmetrical or irregular nature to closely fit a product (often amultipart product) which is of a nonsymmetrical shape or recessed.

Thus, in a typical performance of the method of this invention, a firstfilm is stretched to define a pocket for receiving the product to bepackaged. This pocket is contoured to the shaped of the unit(s) to bepackaged and is provided with ridges which correspond in shape, size andposition to the recesses on one side of the unit(s). The unit(s) arethen positioned in the pocket with the recesses of the unit(s) inalignment with said ridges. A second film then is contoured to fit aboutthe top of the unit(s) resting in the pocket. The films are providedwith peripheral borders that can be sealed together to form the package.Only after at least one of the films has been contoured to the producttherebetween is a vacuum applied to evacuate the interior of thepackage. Following this evacuation and collapsing of the package byexternal air pressure, the package is sealed to prevent the readmissionof air.

I claim:

1. Apparatus for sealing in plastic, with a minimum of enclosed oxygen,a product of irregular shape having a plurality of recesses in thesurface thereof and which is deleteriously affected by the presence ofoxygen; said apparatus comprising a mold having a plurality of separableparts, said mold having internal Walls defining an internal cavity ofsaid irregular shape with spaced, raised Wall portions corresponding tothe recesses in the surface of the product and adapted to be insertedtherein, the spaces between the raised wall portions formingdepressions, a separate vacuum port for each of said depressionsextending through said mold to a respective one of said depressions;said apparatus including means communicating with said internal cavityfor evacuating air from within the package.

References Cited UNITED STATES PATENTS 2,609,301 9/1952 Lindsey 991743,129,545 4/1964 Sloan et a1 53112 1,387,805 8/1921 Roberts 53-184 X2,155,445 4/ 1939 Pittenger 5322 X 2,888,787 6/1959 Cloud 53-184 XWILLIAM W. DYER, IR., Primary Examiner.

FRANK E. BAILEY, Examiner.

R. J. ALVEY, P. H. POHL, Assistant Examiners.

1. APPARATUS FOR SEALING IN PLASTIC, WITH A MINIMUM OF ENCLOSED OXYGEN,A PRODUCT OF IRREGULAR SHAPE HAVING A PLURALITY OF RECESSES IN THESURFACE THEREOF AND WHICH IS DELETERIOUSLY AFFECTED BY THE PRESENCE OFOXYGEN; SAID APPARATUS COMPRISING A MOLD HAVING A PLURALITY OF SEPARABLEPARTS, SAID MOLD HAVING INTERNAL WALLS DEFINING AN INTERNAL CAVITY OFSAID IRREGULAR SHAPE WITH SPACED, RAISED WALL PORTIONS CORRESPONDING TOTHE RECESSES IN SURFACE OF THE PRODUCT AND ADAPTED TO BE INSERTEDTHEREIN, THE SPACES BETWEEN THE RAISED WALL PORTIONS FORMINGDEPRESSIONS, A SEPARATE VACUUM PORT FOR EACH OF SAID DEPRESSIONSEXTENDING THROUGH SAID MOLD TO A RESPECTIVE ONE OF SAID DEPRESSIONS; ANDAPPARATUS INCLUDING MEANS COMMUNICATING WITH SAID INTERNAL CAVITY FOREVACUATING AIR FROM WITHIN THE PACKAGE.